GitHub is a software repository powered by Git. Does not seem to have any site issues, often 24 hours uptime (see site status). Looks pretty sunny at the moment, but when disaster strikes it would be a problem archiving the private repositories.

As of 12th August 2012: 1,963,652 people hosting over 3,460,582 repositories 1,117,147 public repositories are forks, which greatly reduces the amount of data required to archive it.

Backup tools

"git clone" is the simplest one. However, it does not get some project data that is not stored in git, including issue reports, comments, pull requests.

github-backup runs in a git repository and chases down that information,
committing it to a "github" branch. It also chases down the forks and efficiently downloads them as well.

githubarchive.org is creating an archive of the github "timeline", that is, all events like git pushes, forks, created issues, pull requests, … .